Sashin Rabewar Jirgin Sama (ASU) na'ura ce da ke amfani da iska a matsayin abinci, matsawa da sanyaya shi zuwa yanayin zafi, kafin raba iskar oxygen, nitrogen, argon, ko sauran kayayyakin ruwa daga iska mai ruwa ta hanyar gyarawa. Dangane da buƙatun mai amfani, samfuran ASU na iya kasancewa ɗaya (misali, nitrogen) ko maɗaukaki (misali, nitrogen, oxygen, argon). Tsarin na iya samar da samfuran ruwa ko gas don biyan buƙatun abokin ciniki daban-daban.